As the title says, I'm asking to make runes free, and for a number of reasons.
First of all, they are a key element to the game, as a 15-ish AD or 20-ish AP bonus is great, and should be allowed for everybody to have. It's happened quite some times to me where I won ranked games simply because the enemy either had no runes or had the wrong runes, thus I won lane and snowballed to victory.
Second, runes currently are extremely expensive. One of the problems that I had was that when I was new to the game, I was told to waste no IP until level 20, to get some tier 3 runes. However when I did that, I had not more than 5-7 champions, and the ones I had were at 450 or 1350 IP. It is also extremely frustrating to save up ~800IP just to get a flat health seal (+8 health).
Third, They probably don't affect Riot's income negatively because they are bought with IP, but can actually improve Riot's income by a slight bit if made free. Pretty simple, if people can play at equal circunstances, without one having a huge disadvantage against an opponent because the enemy farmed IP until level 20 for runes and you didn't, it makes players enjoy this game more and might invest real money into it. The only slight downside I can think of for Riot's earnings would be that people wouldn't buy as many champions / rune pages with RP because all their IP could be reverted to rune pages and champions, but a happier player base should be prioritized over a slight reduce in income.
However, rune pages could remain as they are, simply because having 2 filled rune pages against 3 or 4 isn't nearly as game breaking as having 2 almost empty rune pages against 2 filled ones, and because some people actually spent their real money into the rune page bundle, and it would be really bad if they found out later that the RP they wasted on it went to waste.
Those are my three main reasons why runes should cost no IP at all.